Heat bursts occur with some frequency in the mountains during the summer monsoon, but are more rare in the Midwest.

They can happen when thunderstorms collapse at the end of their life cycle. As moist air from the storm descends from above, the air cools and drys out initially. Then the air warms rapidly during the last several thousand feet of descent, and compresses when it reaches the ground.

Both the adiabatic warming of descent (Chinook like warming) and compression heating cause temperatures to spike rapidly, and a heat burst is in progress.

At 12:22 a.m. the temperature at Wichita’s Mid-Continent Airport was 85 degrees. At 12:44 the temperature spiked to 102 degrees. This was a 17 degree increase in only 20 minutes. Winds gusted to near 60 mph.

Hourly observations show “heat burst” in Wichita. Also note the dramatic dew point drop from 66 to 27 in an hour!

Temperatures and dew points returned quickly to “air mass” values as the localized heat burst mixed out into the broader atmosphere.

An interesting weather phenomena called a “Heat Burst” happened over west central and central Minnesota during the overnight hours of Sunday July 16th to Monday July 17th. A heat burst is caused by a dying thunderstorm with very warm air aloft. The temperature at Canby jumped from 91 degrees to 100 degrees in 40 minutes (from 10:35 pm to 11:15 pm) at the same time the dew point dropped from 63 to 32 degrees.

LOCATION TIME TEMP DEW POINT MAX WIND GUST

————————————————————-

CANBY 1115 PM 100 (+9) 32 (-38) 63 MPH

APPLETON 1255 AM 91 (+14) 54 (-22) 37 MPH

MONTEVIDEO 115 AM 90 (+6) 52 (-16) 23 MPH

BENSON 135 AM 97 (+15) 37 (-36) 37 MPH

WILLMAR 235 AM 97 (+18) 45 (-28) 44 MPH

PAYNESVILLE 235 AM 88 (+7) 57 (-15) 24 MPH

Here’s what seems to be a credible list of heat bursts from Wikipedia.

-Midland, Texas, June 16, 2008: At 11:25 pm a wind gust of 62 mph (100 km/h) occurred, and the temperature rose from 71 °F (21.7 °C) to 97 °F (36.1 °C) in minutes.[8] (These measurements were taken from miles away, and theories point to 80-100 mph (130-160 km/h) winds in a 2-3 block perimeter.)[9]

-Emporia, Kansas, 25 May 2008: Reported temperature jumped from 71 °F (21.7 °C) to 91 °F (32.8 °C) between 4:44 am and 5:11 am (CDT)[10] as the result of wind activity from a slow moving thunderstorm some 40 miles (64 km) to the southwest.

–Canby, Minnesota, 16 July 2006: A heat burst formed in Western Minnesota, pushing Canby’s temperature to 100 °F (37.8 °C), and causing a wind gust of 63 mph (55 kn; 101 km/h). The dew point fell from 70 °F (21.1 °C) to 32 °F (0 °C) over the course of one hour.[11]

-Minnesota and South Dakota, March 26, 1998: A temperature increase of 10-20 °F (6-11 °C) was reported in the towns of Marshall, Minnesota, Sioux Falls, South Dakota, Brookings, South Dakota, and Montrose, South Dakota during a two-hour period.[16]

-Oklahoma, May 22-May 23, 1996: The temperature in the towns of Chickasha rose from 87.6 °F (30.9 °C) to 101.9 °F (38.8 °C) in just 25 minutes, while the temperature at Ninnekah rose from 87.9 °F (31.1 °C) to 101.4 °F (39 °C) in 40 minutes. In addition, wind damage was reported as winds gusted to 95 mph (153 km/h) in Lawton,67 mph (108 km/h) in Ninnekah, and 63 mph (101 km/h) in Chickasha.[17]

-Kopperl, Texas, 1960: A heat burst sent the air temperature to near 140 °F (60 °C), supposedly causing cotton crops to become desiccated and drying out vegetation.[18]

Portugal, July 6, 1949: A heat burst reportedly drove the air temperature from 38 °C (100.4 °F) to 70 °C (158.0 °F) two minutes later (note that the highest temperature formally recognized on the Earth is57.8 °C (136.0 °F) in Libya in 1922, and the former record has not been verified).[19]

-Cherokee, Oklahoma, 11 July 1909: at 3:00 in the morning, a heat burst south of Cherokee, Oklahoma reportedly caused the temperature to rise briefly to 136 °F (57.8 °C), desiccating crops in the area.[20]

About the blogger

Paul Huttner is chief meteorologist for Minnesota Public Radio. Huttner has worked TV and radio stations in Minneapolis, Tucson and Chicago. Paul is a graduate of Macalester College in St. Paul and holds a bachelor’s degree in geography with an emphasis in meteorology.